In such a machine, it is desirable to have the gauge wheels positioned on the opposite sides of the furrow opening disk in a close relationship to accurately gauge the depth of the furrow and to prevent the build-up of dirt or trash between the gauge wheels and the opening disks. Due to the wear of the machine, it is sometimes necessary to adjust the position of the gauge wheels to maintain the close relationship of the wheels with the opening disks. For that purpose, it is known to provide shims or spacer washers on the opposite side of the arm that rotatably supports the gauge wheels, the upper, inner or proximate end of the arm being mounted on a generally transverse shaft so that the lateral position of the gauge wheel relative to the adjacent disk can be adjusted by removing the bolt that holds the gauge wheel arm until the desired minimum clearance between the gauge wheel and the side of the furrow opening disk is achieved. The above procedure, of course, may be somewhat difficult and time consuming, since to make the adjustment, the gauge wheel arm and the gauge wheel mounted thereon must be removed and replaced to add or subtract the washers or shims, usually multiple times.
Other conventional devices that provide for axial adjustment of the gauge wheel are merely adequate for the intended purpose in design, but in practice are disadvantageous because of a high rate of wear of the central most expensive component, the gauge arm. One prior art device provides axially adjustment of the position of the gauge wheels in connection with the adjacent furrow opening devices and claims to alleviate excessive wear on the bearings by securing the bearing to the frame, which results in undesireable wear of the gauge wheel arm. Another prior art design provides a bushing for mounting the gauge wheel arm that has both a threaded portion as well as one or two smooth cylindrical portions. The threaded portion enables the gauge wheel arm to be a laterally adjusted while the smooth portion or portions purport to provide a bearing surface or surfaces for the gauge wheel arm loads. This is purported to remove the load from the threads, reducing wear of both the bushing and the gauge wheel arm, thereby reducing maintenance cost. However, experience has shown otherwise. Since the gauge wheel arm still moves or pivots about the bushing, there is wear on the engaged threads with every movement of the gauge wheel arm with respect to the bushing.
Therefore, there is a need in the art for simple, inexpensive solution to mount a laterally adjustable gauge wheel arm that does not wear the threads of the gauge wheel arm by rotational friction, that is long lasting and that overcomes the disadvantages of the unreliable or complex prior art systems.